U.S. patent application number 16/198045 was filed with the patent office on 2020-05-21 for channeled reductant mixing device.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Yong Shah Yi. Invention is credited to Ian Aguirre, Yung T. Bui, Arvind Jujare, Erin Reim, Anthony C. Rodman, Samprati Vijay Shah, Yong Yi.
Application Number | 20200156093 16/198045 |
Document ID | / |
Family ID | 70546355 |
Filed Date | 2020-05-21 |
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United States Patent
Application |
20200156093 |
Kind Code |
A1 |
Yi; Yong ; et al. |
May 21, 2020 |
CHANNELED REDUCTANT MIXING DEVICE
Abstract
A reductant impingement device includes a proximal end having an
impingement pin with a convex surface; and a distal end having a
body concentric with a longitudinal axis of the impingement pin.
The distal end includes a first surface and a second surface
opposite the first surface. A plurality of inner channels connects
the first surface and the second surface, and a plurality of outer
channels connects the first surface and the second surface, where
the plurality of inner channels are disposed in a circular array at
a first radial distance from a longitudinal axis of the impingement
pin, and the plurality of outer channels are disposed in a circular
array at a second distance from the longitudinal axis of the
impingement pin.
Inventors: |
Yi; Yong; (Dunlap, IL)
; Shah; Samprati Vijay; (Peoria, IL) ; Aguirre;
Ian; (Peoria, IL) ; Bui; Yung T.; (Peoria,
IL) ; Jujare; Arvind; (Peoria, IL) ; Reim;
Erin; (South Bend, IN) ; Rodman; Anthony C.;
(Peoria, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yi; Yong
Shah; Samprati Vijay
Aguirre; Ian
Bui; Yung T.
Jujare; Arvind
Reim; Erin
Rodman; Anthony C. |
Dunlap
Peoria
Peoria
Peoria
Peoria
South Bend
Peoria |
IL
IL
IL
IL
IL
IN
IL |
US
US
US
US
US
US
US |
|
|
Assignee: |
Caterpillar Inc.
Deerfield
IL
|
Family ID: |
70546355 |
Appl. No.: |
16/198045 |
Filed: |
November 21, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B 7/0466 20130101;
B05B 5/00 20130101; B05B 11/06 20130101; B05B 1/02 20130101; B05B
3/00 20130101 |
International
Class: |
B05B 7/04 20060101
B05B007/04; B05B 11/06 20060101 B05B011/06 |
Claims
1. A nozzle, comprising: a nozzle body comprising: a proximal end
including a first inlet disposed in a direction along a
longitudinal axis of the nozzle and a second inlet comprising a
first air inlet channel disposed at an angle perpendicular to the
longitudinal axis of the nozzle; a distal end disposed opposite the
proximal end along the longitudinal axis of the nozzle, the distal
end comprising an outlet; and an interior disposed between the
proximal end and the distal end, the interior including: a fluid
impingement chamber fluidly connected with the first inlet and the
second inlet, and a mixing chamber fluidly connected with the
outlet at the distal end; and an impingement device fluidly
connecting the fluid impingement chamber and the mixing chamber,
the impingement device comprising: an impingement pin comprising a
pin body and a convex surface disposed at an end of the impingement
pin, wherein the convex surface is concentric with the longitudinal
axis of the nozzle.
2. The nozzle of claim 1, wherein the first inlet is a reductant
fluid inlet and the second inlet is a compressed air inlet.
3. The nozzle of claim 1, wherein the convex surface is a
substantially hemispherical and disposed at the end of the
impingement pin, wherein the convex surface is configured to
impinge a fluid flow of a fluid passing through the first
inlet.
4. The nozzle of claim 1, wherein the impingement device comprises
an impingement device body having a first surface and a second
surface, wherein one or more of the first surface and the second
surface is configured to create a connection that mates with a
surface of the interior such that the connection fluidly seals the
fluid impingement chamber and the mixing chamber, wherein fluid can
substantially pass through the impingement device body through a
plurality of orifices disposed in the impingement device body.
5. The nozzle of claim 1, wherein the first air inlet channel is
disposed opposite to the pin body of the impingement pin such that
a central longitudinal axis of the first air inlet channel is
substantially perpendicular to an outer surface of the pin body of
the impingement pin, and substantially perpendicular to the
longitudinal axis.
6. The nozzle of claim 5, further comprising a second air inlet
channel disposed opposite to the pin body of the impingement pin
such that a central longitudinal axis of the second air inlet
channel is substantially perpendicular to the outer surface of the
pin body of the impingement pin, and substantially perpendicular to
the longitudinal axis.
7. The nozzle of claim 1, wherein the impingement device further
comprises a second longitudinal axis coaxial with the longitudinal
axis of the nozzle, the impingement device further comprising: a
plurality of orifices circumferentially disposed around the second
longitudinal axis.
8. The nozzle of claim 7, wherein the plurality of orifices are
substantially equally circumferentially distributed around the
longitudinal axis of the nozzle.
9. The nozzle of claim 8, wherein the plurality of orifices
comprises a first plurality of orifices having a first
predetermined angle with respect to a first surface of the
impingement device and a second plurality of orifices having a
second angle with respect the first surface of the impingement
device.
10. An impingement device comprising: an impingement pin and a
device body coaxial with a longitudinal axis of the impingement
pin, and disposed to the impingement pin at a distal end of the
impingement device; wherein the impingement pin comprises: a convex
surface of the impingement pin at a proximal end of the device; and
wherein the device body comprises: a first surface; a second
surface opposite the first surface; and a plurality of inner
channels connecting the first surface and the second surface, the
plurality of inner channels disposed in a first circular array at a
first radial distance from a longitudinal axis of the impingement
pin; and a plurality of outer channels connecting the first surface
and the second surface, the plurality of outer channels disposed in
a second circular array at a second radial distance from the
longitudinal axis of the impingement device.
11. The impingement device of claim 10 further comprising a
plurality of slits forming the plurality of inner channels
connecting the first surface and the second surface.
12. The impingement device of claim 11, wherein a first inner
channel of the plurality of inner channels comprises two opposing
inner channel walls, wherein the two opposing inner channel walls
comprise a first inner channel wall disposed substantially parallel
to a second inner channel wall, and wherein the first inner channel
wall and the second inner channel wall are disposed at a first
predetermined angle respective to the longitudinal axis of the
impingement pin.
13. The impingement device of claim 11, wherein a first outer
channel of the plurality of outer channels comprises two opposing
outer channel walls, wherein the two opposing outer channel walls
comprise a first outer channel wall disposed substantially parallel
to a second outer channel wall, and wherein the first outer channel
wall and the second outer channel wall are disposed at a second
predetermined angle respective to the longitudinal axis of the
impingement pin.
14. The impingement device of claim 11, wherein the convex surface
is substantially hemispherical and disposed at the end of the
impingement pin, wherein the convex surface is configured to
impinge a fluid flow of a fluid.
15. An exhaust system, comprising: an exhaust pipe configured to
receive exhaust from an engine; a compressed air source; a
reductant source; and a nozzle fluidly connected with the exhaust
pipe, the nozzle configured to receive compressed air from the
compressed air source and reductant from the reductant source, the
nozzle having a nozzle body comprising: a proximal end including a
first inlet disposed in a direction along a longitudinal axis of
the nozzle and a second inlet comprising a first air inlet channel
disposed at an angle perpendicular to the longitudinal axis of the
nozzle; a distal end disposed opposite the proximal end along the
longitudinal axis of the nozzle, the distal end comprising an
outlet; an interior disposed between the proximal end and the
distal end, the interior including: a fluid impingement chamber
fluidly connected with the first inlet and the second inlet, and a
mixing chamber fluidly connected with the outlet at the distal end;
and an impingement device fluidly connecting the fluid impingement
chamber and the mixing chamber, the impingement device comprising:
an impingement pin comprising a pin body and a convex surface
disposed at an end of the impingement pin, wherein the convex
surface is concentric with the longitudinal axis of the nozzle.
16. The exhaust system of claim 15, wherein the first inlet is a
reductant fluid inlet and the second inlet is a compressed air
inlet.
17. The exhaust system of claim 15, wherein the convex surface is
substantially hemispherical and disposed at the end of the
impingement pin, wherein the convex surface is configured to
impinge a fluid flow of a fluid passing through the first
inlet.
18. The exhaust system of claim 15, impingement device comprises an
impingement device body having a first surface and a second
surface, wherein one or more of the first surface and the second
surface is configured to create a connection that mates with a
surface of the interior such that the connection fluidly seals the
fluid impingement chamber and the mixing chamber, wherein fluid can
substantially pass through the impingement device body through a
plurality of orifices disposed in the impingement device body.
19. The exhaust system of claim 15, wherein the first air inlet
channel is disposed opposite to the pin body such that a central
longitudinal axis of the first air inlet channel is substantially
perpendicular to an outer surface of the pin body of the
impingement pin, and substantially perpendicular to the
longitudinal axis.
20. The exhaust system of claim 19, further comprising a second air
inlet channel disposed opposite to the pin body such that a central
longitudinal axis of the second air inlet channel is substantially
perpendicular to the outer surface of the pin body of the
impingement pin, and substantially perpendicular to the
longitudinal axis.
Description
TECHNICAL FIELD
[0001] The present disclosure is directed to an exhaust treatment
system and, more particularly, to a nozzle that injects a reductant
solution into a fluid path within an exhaust treatment system.
BACKGROUND
[0002] Internal combustion engines, such as diesel engines,
gasoline engines, gaseous fuel-powered engines, and other engines
known in the art, exhaust a complex mixture of components into the
environment. These components may include nitrogen oxides (NOx),
such as NO and NO.sub.2. Due to an increased focus on avoiding
environmental pollution, exhaust emission standards are becoming
more stringent, and in some instances, the amount of NOx emitted
from engines may be regulated depending on engine size, engine
class, and/or engine type. To ensure compliance with the regulation
of these components, as well as reduce environmental effects, some
engine manufacturers implement a strategy called Selective
Catalytic Reduction (SCR). SCR is a process where gaseous and/or
liquid reductant, most commonly urea ((NH.sub.2).sub.2CO), is
selectively added to engine exhaust using one or more nozzles. The
injected reductant decomposes into ammonia (NH.sub.3), reacts with
the NOx in the exhaust, and forms water (H.sub.2O) and diatomic
nitrogen (N.sub.2).
[0003] U.S. Pat. No. 8,356,473 to Blomquist, issued on Jan. 22,
2013 (hereinafter referred to as the '473 reference), describes an
injection device having a first conduit for supplying compressed
gas, and a second conduit arranged on the outside of the second
conduit for supplying a liquid agent. At least one hole extends
between the first conduit and the second conduit. As discussed in
the '473 reference, liquid agent flows through the at least one
hole into the compressed air. The liquid agent is atomized by the
compressed gas, mixed with the compressed gas, and transported
through an outlet of the injection device for dispersion into an
exhaust line.
[0004] While the injection device of the '473 reference may attempt
to increase the atomization of the liquid agent, the operation of
the injection device may be suboptimal. For example, the injection
device described in the '473 reference is relatively small in size,
and due to low turbulence and mixing features, effective mixing of
the liquid agent may be difficult to achieve. Further, the '473
reference describes an injection device having multiple distinct
and assembled parts, and such a device configuration may increase
the size, complexity, assembly time, and/or manufacturing cost of
the nozzle. Such multi-part devices are also often difficult to
clean and may become clogged easily.
[0005] Example embodiments of the present disclosure are directed
toward overcoming one or more of the deficiencies described
above.
SUMMARY OF THE INVENTION
[0006] According to one embodiment of the present disclosure, a
nozzle, is described that includes a nozzle body. The nozzle body
includes proximal end having a first inlet disposed in a direction
along a longitudinal axis of the nozzle, and a second inlet having
a first air inlet channel disposed at an angle perpendicular to the
longitudinal axis of the nozzle. The nozzle includes a distal end
disposed opposite the proximal end along the longitudinal axis of
the nozzle, the distal end having an outlet. An interior of the
nozzle is disposed between the proximal end and the distal end, and
includes a fluid impingement chamber that is fluidly connected with
the first inlet and the second inlet, and a mixing chamber fluidly
connected with an outlet at the distal end. The nozzle also
includes an impingement device fluidly connecting the fluid
impingement chamber and the mixing chamber. The impingement device
includes an impingement pin with a pin body and a convex surface
disposed at an end of the impingement pin. The convex surface is
concentric with the longitudinal axis of the nozzle.
[0007] According to another embodiment of the present disclosure,
an impingement device includes an impingement pin and a device body
coaxial with a longitudinal axis of the impingement pin. The device
body is disposed to the impingement pin at a distal end of the
impingement device. The impingement pin includes a convex surface
at a proximal end of the device. The device body includes a first
surface, a second surface opposite the first surface, and a
plurality of inner channels connecting the first surface and the
second surface. The plurality of inner channels are disposed in a
first circular array at a first radial distance from a longitudinal
axis of the impingement pin. The device body further includes a
plurality of outer channels connecting the first surface and the
second surface. The plurality of outer channels is disposed in a
second circular array at a second radial distance from the
longitudinal axis of the impingement pin.
[0008] According to yet another embodiment, an exhaust system is
described. The exhaust system includes an exhaust pipe configured
to receive exhaust from an engine, a compressed air source, a
reductant source, and a nozzle fluidly connected with the exhaust
pipe. The nozzle is configured to receive air from the compressed
air source and reductant from the reductant source. The nozzle
includes an impingement pin and a device body coaxial with a
longitudinal axis of the impingement pin. The device body is
disposed to the impingement pin at a distal end of the impingement
device. The impingement pin includes a convex surface at a proximal
end of the device. The device body includes a first surface, a
second surface opposite the first surface, and a plurality of inner
channels connecting the first surface and the second surface. The
plurality of inner channels are disposed in a first circular array
at a first radial distance from a longitudinal axis of the
impingement pin. The device body further includes a plurality of
outer channels connecting the first surface and the second surface.
The plurality of outer channels is disposed in a second circular
array at a second radial distance from the longitudinal axis of the
impingement pin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a reductant nozzle of an
exhaust system, according to an embodiment of the present
disclosure.
[0010] FIG. 2 depicts a perspective view of a reductant impingement
device for use in the reductant nozzle of FIG. 1, according to an
embodiment of the present disclosure.
[0011] FIG. 3 depicts a top view of the reductant impingement
device shown in FIG. 2, according to an embodiment of the present
disclosure.
[0012] FIG. 4 is a front view of the reductant impingement device
shown in FIG. 2, according to an embodiment of the present
disclosure.
[0013] FIG. 5 depicts a section view of an inner channel of the
reductant impingement device of FIGS. 2-4, according to an
embodiment of the present disclosure.
[0014] FIG. 6 depicts a section view of an outer channel of the
reductant impingement device of FIGS. 2-4, according to an
embodiment of the present disclosure.
[0015] FIG. 7 is a schematic view of an exhaust system having a
reductant nozzle, according to an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0016] This disclosure generally relates to nozzles useful for
injecting a mixture of reductant and air into an exhaust stream.
Wherever possible, the same reference number(s) will be used
through the drawings to refer to the same or like features. In the
figures, the left-most digit(s) of a reference number identifies
the figure in which the reference number first appears.
[0017] FIG. 1 illustrates an example nozzle 100. For the purposes
of this disclosure, the nozzle 100 is shown and described in use
with a diesel-fueled, internal combustion engine. However, the
nozzle 100 may embody a reductant nozzle operative as part of any
exhaust system useable with any other type of combustion engine
such as a gasoline or a gaseous fuel-powered engine, or an engine
fueled by compressed or liquefied natural gas, propane, or
methane.
[0018] Selective Catalytic Reduction (SCR) is an active emissions
control technology system that injects a liquid reductant agent
through a catalyst into the exhaust stream of a diesel engine. The
reductant source is usually automotive-grade urea, otherwise known
as Diesel Exhaust Fluid (DEF). In some embodiments, the reductant
may include DEF, an ammonia gas, liquefied anhydrous ammonia,
ammonium carbonate, an ammine salt solution, a hydrocarbon such as
diesel fuel, or another solution. In DEF reactions, the DEF sets
off a chemical reaction that converts nitrogen oxides into
nitrogen, water and tiny amounts of carbon dioxide (CO2), natural
components of the air we breathe, which is then expelled through
the vehicle tailpipe. Embodiments of the present disclosure may
reduce emissions increasing the effectiveness of SCR systems in the
emission control of diesel combustion engines.
[0019] An engine (not shown in FIG. 1) may produce an exhaust
stream 102. The nozzle 100 may inject reductant into the exhaust
stream 102. The nozzle 100 is configured to spray a reductant
solution (or other compound(s)) into the exhaust stream 102. The
nozzle 100 may include a proximal end 104 and a distal end 106
disposed opposite the proximal end 104. The nozzle 100 may fluidly
connect a supply line (not shown in FIG. 1) that supplies reductant
(not shown) to a first inlet 108, which may be an inlet for
reductant, at the proximal end 104 of the nozzle 100, and via one
or more fittings or couplers (not shown). The nozzle 100 may
include a compressed air inlet channel 142 that can be fluidly
connected to a supply of compressed air for supplying the
compressed air 116 to a second inlet 110. As explained in greater
detail hereafter, the nozzle 100 may be configured to mix reductant
solution 114 and compressed air 116 in extreme heat environments
such that the reductant maintains an operative temperature without
reductant crystallization that may clog the nozzle.
[0020] In some embodiments, the nozzle 100 may be manufactured
using 3D printing techniques or other types of additive
manufacturing (e.g., cast molding) and comprise a single piece of
material. However, it is contemplated that one more of the
components of the nozzle 100 discussed above and herein may be
alternatively manufactured from other processes including manual
machining, computer numeric controlled (CNC) machining, or with
other methods. Additionally, the nozzle 100 may be manufactured
from a plurality of materials, including chromium, nickel,
stainless steel, alloys, ceramics, etc. The materials may also be
anti-corrosive and anti-stick to prevent a build-up of the
reductant on and/or within the nozzle 100.
[0021] At the proximal end 104 of the nozzle 100, the nozzle 100
may include one or more inlets configured to receive reductant
and/or air from the first air inlet channel 142. For example, the
nozzle 100 may include a first inlet 108 for supplying the
reductant solution 114 to the nozzle 100, and a second inlet 110
for supplying compressed air 116 to the nozzle 100.
[0022] In some examples, at the distal end 106 of the nozzle 100,
the nozzle 100 can include one or more spray channel outlet(s) 112.
According to embodiments described herein, a reductant/air solution
120 may enter the exhaust stream 102 through the one or more spray
channel outlet(s) 112.
[0023] As discussed in detail herein, the nozzle 100 may facilitate
mixing of reductant solution 114 and compressed air 116 to mix,
aerate, separate, and/or atomize the reductant solution 114.
According to an embodiment, an interior 118 of the nozzle 100
comprises a structure of the nozzle 100, where the structure
comprises various passages and channels formed at least partly by
the body of the nozzle 100. More particularly, within the nozzle
interior 118 of the nozzle 100, air and reductant may mix together
to form the reductant/air solution 120. This process may cause the
reductant solution 114 to break up into fine particles or droplets
at the interior first end 122 of the nozzle interior 118, and mix
with the compressed air 116 at an interior second end 124 of the
nozzle interior 118. As noted above, the nozzle 100 may disperse
and/or otherwise direct the reductant/air solution 120 into the
exhaust stream 102 through the one or more spray channel outlet(s)
112 disposed at the distal end 106 of the nozzle 100. Accordingly,
as the reductant/air solution 120 disperses into the exhaust stream
102, the reductant/air solution 120 may react with NOx (e.g., NO
and/or NO.sub.2) to form water (H.sub.2O) and elemental nitrogen
(N.sub.2).
[0024] According to an embodiment, the nozzle interior 118 may be
bifurcated into two or more main chambers (e.g., the fluid
impingement chamber 426 and the mixing chamber 128) by an
impingement device 130. In some aspects, the impingement device 130
may fluidly connect the fluid impingement chamber 426 and the
mixing chamber 128 via a plurality of orifices 138 that provide
channels for the reductant/air solution 120 to pass from the fluid
impingement chamber 426 to the mixing chamber 128. More
particularly, an impingement device body 132 may be configured as a
substantially flat disk or plate having an impingement pin 134 at a
center of the impingement device body 132, where the impingement
device body 132 seals against one or more mating surfaces such that
reductant solution 114, compressed air 116, and/or reductant/air
solution 120 may not pass through the impingement device 130 from
the fluid impingement chamber 426 to the mixing chamber 128 except
for through the plurality of orifices 138.
[0025] As explained in greater detail hereafter, the impingement
pin 134 includes a convex surface 136 at a proximal end of the
impingement device 130. In operation, the reductant solution 114
may be pumped or otherwise conveyed into the first inlet 108.
Accordingly, when pumped into the nozzle 100, the reductant
solution 114 travels through first inlet 108 and strikes the convex
surface 136, where an approximate center of a laminar flow of the
reductant solution 114 (the reductant solution 114 and the laminar
flow of the reductant solution 114 depicted as an arrow in FIG. 1)
strikes the convex surface 136 (approximately) at the apex of the
convex surface 136.
[0026] The shape and position of the convex surface 136 is such
that upon impinging the convex surface 136, the reductant solution
114 is dispersed into a mixture of ambient air and reductant
solution. In some aspects, the orifices 138, which connect the
fluid impingement chamber (where the fluid is broken up by the
impingement pin 134) and the mixing chamber 128, are configured to
further disperse the reductant and compressed air solution into
smaller discrete droplets. For example, the orifices 138 can be
configured to break the reductant/air mixture into droplets,
atomize the reductant and air solution in part, or otherwise reduce
the reductant and solution into an aerosol/droplet mixture. As
explained in detail hereafter, the orifices 138 may also be
configured to create turbulence in the mixing chamber 128 to
further combine the compressed air 116 and the reductant solution
114, and form the reductant/air solution 120.
[0027] When the reductant solution is urea or contains urea, in
some instances, the urea may react with heat such that
crystallization of the reductant solution can occur above certain
temperatures. Because the nozzle 100 may be operable as part of an
exhaust system of a combustion engine, the nozzle 100 can reach
temperatures ranging between approximately 200.degree. C. to
approximately 500.degree. C. In some examples, the urea-water
solution of reductant solution may crystalize at these high
temperatures (e.g., between approximately 200.degree. C. and
approximately 500.degree. C.), as water evaporates from the
solution. When the urea crystalizes at high temperatures, deposits
of the urea may form that can hinder the performance of the exhaust
system. For example, the selective-catalytic reaction that removes
particulates from the exhaust stream may be hindered by the urea
crystal deposits, the nozzle outlet or other fluid ports may become
clogged, etc.
[0028] To prevent crystallization of the reductant solution 114,
according to an embodiment, the nozzle 100 may channel the
compressed air 116 through a first air inlet channel 142. The
compressed air 116, when mixed with the reductant solution 114, may
cool the system and prevent crystallization of the urea in the
reductant solution 114. Accordingly, the first air inlet channel
142 fluidly connects the second inlet 110 to the fluid impingement
chamber 426. The second inlet channel 110 may direct the compressed
air 116 into the fluid impingement chamber 426 at a predetermined
angle with respect to the longitudinal axis 140. The predetermined
angle of incidence of the compressed air 116 with respect to the
impingement pin 134 may create a turbulent airflow within the fluid
impingement chamber 126. For example, the predetermined angle
between an axis of the first air inlet channel 142 and the
longitudinal axis 140 may be about 90.degree. (substantially
perpendicular). As depicted in FIG. 1, the first air inlet channel
142 may be disposed opposite to a pin body surface of the
impingement pin 134 such that a longitudinal center of the first
air inlet channel 142 is substantially perpendicular to a curved
outer surface of the impingement pin 134, and substantially
perpendicular to the longitudinal axis 140. When the compressed air
116 hits the side of the impingement pin 134 at the predetermined
angle, the compressed air 116 may be forced to mix with the
reductant solution 116 in a way that combines and cools the
impingement pin 134, the fluid impingement chamber 126, and the
reductant solution 114.
[0029] In some aspects, the nozzle 100 may include two or more air
inlet channels. For example, the nozzle 100 may include a second
air inlet channel 144 disposed opposite to the pin body 135 of the
impingement pin 134 such that a longitudinal center of the second
air inlet channel may be substantially perpendicular to the outer
surface of the pin body 135 of the impingement pin 134, and
substantially perpendicular to the longitudinal axis 140. In yet
another embodiment, more than two air inlet channels may be
included at substantially perpendicular angles to the longitudinal
axis 140, such that they are configured to be opposite to the pin
body 135. As used herein, the phrase "opposite to the pin body 135"
means that the pin body 135 may be configured to be directly in the
laminar and/or turbulent flow of a fluid interacting with the pin
body 135.
[0030] By injecting the compressed air 116 at a perpendicular angle
to the longitudinal axis 140, the stream of compressed air 116 may
interact with the curved exterior surface of the impingement pin
134 such that the compressed air 116 disperses at reflective angles
within the fluid impingement chamber 426. For example, the angle of
incidence of the linearly-flowing stream of compressed air 116
equals the angle of reflection of the stream of compressed air 116
as the air stream interacts with the impingement pin 134.
Accordingly, when the radially curved pin body 135 interacts with
the laminar flow of the stream of compressed air 116, the angle of
reflection of the compressed air 116 is spread throughout the fluid
impingement chamber 126. The turbulence caused by the compressed
air 116 interacting with the curved pin body 135f mixes the
compressed air 116 with the reductant solution 114 within the fluid
impingement chamber 426. In combination with the dispersed
reductant solution 114 (dispersed after hitting the convex surface
136), the reductant solution 114 may be cooled by the compressed
air 116, which may be more turbulent and evenly mixed with the
reductant solution 114. Because of the turbulence created by the
combination/configuration of the first air inlet channel 142 and
the reductant solution 114 interacting with the convex surface 136,
the interior surfaces of the nozzle interior 118 may also be cooled
to a temperature below the threshold for urea crystallization.
[0031] The nozzle 100 may be installed directly in the exhaust
stream 102 of an exhaust system (e.g., as shown in FIG. 7,
discussed in greater detail hereafter), in conventional SCR
catalyst systems. Accordingly, in conventional emission systems a
nozzle spraying diesel emission fluid (DEF) may build crystal
deposits of urea, which can foul the exhaust system. In
conventional systems, the nozzle can exceed the crystallization
threshold of temperature for urea in the reductant solution 114.
According to one or more embodiments, a combination of elements may
provide optimal cooling and mixing properties: first, the
compressed air 116 may be forced into the impingement pin 134 at an
angle with respect to the impingement pin 134 that creates
turbulence, and second, the reductant solution 114 may be
interspersed with the turbulent air by the convex surface 136
within the fluid impingement chamber 426 such that the outer
surface of the pin body of the impingement pin 134 may directly
oppose the stream of compressed air 116. According to embodiments,
this configuration the nozzle 100 configuration may cool both the
reductant solution 114 and the nozzle interior 118.
[0032] FIG. 2 depicts a perspective view of an example impingement
device 130 for use in the reductant nozzle of FIG. 1, according to
an embodiment of the present disclosure. FIG. 3 depicts a top view
of the impingement device 130 shown in FIG. 2, according to an
embodiment of the present disclosure. FIG. 4 is a front view of the
impingement device 130 shown in FIG. 2, according to an embodiment
of the present disclosure.
[0033] With reference to FIG. 3, according to one or more
embodiments, the impingement device 130 may include an impingement
device body 132, and the impingement pin 134 disposed to the
impingement device body 132. The impingement device body 132
includes the orifices 138, which may be circumferentially disposed
around the longitudinal axis 140 of the nozzle (FIG. 1), and more
specifically, disposed around a second longitudinal axis
(longitudinal axis 150, as shown in FIG. 4) of the impingement
device 130. When the impingement pin 134 is configured as an
assembly with the nozzle 100 (for example, as depicted in FIG. 1),
the longitudinal axis 140 and second longitudinal axis 150 are
colinear.
[0034] As shown in FIG. 2, the orifices 138 may be configured as
through-channels circumferentially disposed around the second
longitudinal axis 150. In one aspect, the plurality of orifices 138
are substantially equally circumferentially distributed around the
longitudinal axis 140 of the nozzle 100 (and substantially equally
circumferentially distributed around the second longitudinal axis
150).
[0035] In another aspect, the orifices 138 may be configured as two
radial groupings such that one grouping of channels may be at a
first radial distance 154 and the second grouping may be organized
at a second radial distance 158. For example, a plurality of inner
channels 152 may be disposed in circular array at the first radial
distance 154 from the second longitudinal axis 150, and a plurality
of outer channels 156 are disposed in a circular array at the
second radial distance 158 from the second longitudinal axis 150 of
the impingement pin 134. In one aspect, the first radial distance
may be approximately 1/3 of the radial distance of the impingement
device body 132 from the second longitudinal axis 150 to an outer
edge of the impingement device body 132. In another aspect, the
second radial distance may be approximately 2/3 of the radial
distance of the impingement device body 132 from the second
longitudinal axis 150 to an outer edge of the impingement device
body 132. In other examples, the distance may be greater than or
less than the radial distance of the impingement device body 132,
such as, for example, 1/2 of the radial distance, 11/16 of the
radial distance, etc.
[0036] With reference to the front view of the impingement pin 134
in FIG. 4, the pin body 135 of the impingement pin 134 is depicted
with the convex surface 136 at a proximal end 146 of the pin body
135. The convex surface 136 of the impingement device 130 may be
configured to oppose a flow direction of a fluid flow of the first
inlet 108 of the nozzle 100 (FIG. 1). The convex surface 136 may be
substantially hemispherical, according to an embodiment. The
hemispherical shape is shown to disperse the reductant solution 114
(FIG. 1) in a way such that mixing of the reductant solution 114
with the compressed air 116 results in optimal cooling of the
reductant/air solution 120.
[0037] Another benefit of the convex surface 136 may be ease of
manufacture of the impingement device 130. In some embodiments, the
impingement pin 134 may be machined from or otherwise manufactured
as a unitary piece with respect to the impingement device body 132.
In another embodiment, the impingement pin 134 may be a separate
part from the impingement device body 132, and removably disposed
to the impingement device body 132 using a mechanical fastener (not
shown). In either case, the convex surface 136 may provide an
optimal dispersing affect without introduction of multiple
machining steps or extraneous parts to assemble.
[0038] With continued reference to FIG. 4, a first surface 147 may
be configured to seal against an interior lip of the nozzle
interior 118 such that the fluid impingement chamber 426 may be
fluidly separate from the mixing chamber 128, except for the
orifices 138 (which include plurality of inner channels 152, and
the plurality of outer channels 156). With reference to FIG. 3, a
partial top view of the orifices 138 is depicted (and more
particularly, an inner channel 160, and an outer channel 162, of
the orifices 138 is depicted). For the sake of simplicity of
explanation, the top view in FIG. 3 shows only one inner channel
160 and one outer channel 162, although it should be appreciated
that the plurality of channels (the orifices 138) may include any
number of channels.
[0039] The inner channel 160 may be configured to direct fluid
(e.g., the reductant solution 114, the compressed air 116, and/or
the reductant/air solution 120) in a direction generally consistent
with a channel direction 164. The outer channel 162 may be
configured to direct fluid (e.g., the reductant solution 114, the
compressed air 116, and/or the reductant/air solution 120) in a
direction generally consistent with a directional arrow showing a
channel direction 166. The inner channel 160 may be representative
of the channel direction for all of the inner channels of the
plurality of orifices 138 circumferentially disposed around the
second longitudinal axis 150. The inner channel 160 fluidly
connects the first surface 147 and the second surface 149.
[0040] According to another embodiment, the channel direction 164
and the channel direction 166 may be configured in another pattern
such that the direction changes at every two channels, every three
channels, etc. within the same radial distance. Other
configurations are contemplated.
[0041] FIG. 5 depicts a section view of an inner channel of the
reductant impingement device of FIGS. 2-4, according to an
embodiment of the present disclosure. The channel direction 164
indicates a general trajectory of any fluids passing through the
inner channel 160. The inner channel 160 may be configured as a
slit having two opposing inner channel walls. In one embodiment,
the two inner channel walls can include a first inner channel wall
168 that may be disposed substantially parallel to a second inner
channel wall 170. The two opposing channel walls form two sides of
the inner channel 160. In one aspect, the first inner channel wall
168 and the second inner channel wall 170 are disposed at a first
predetermined angle 172 with respect to the longitudinal axis of
the impingement pin 134 (e.g., the second longitudinal axis 150).
In one aspect, the first predetermined angle may be approximately
30.degree. in another aspect, the first predetermined angle may be
another angle such as, for example, 25.degree., or 35.degree., or
greater or less than 25.degree., or 35.degree..
[0042] FIG. 6 depicts a section view of an outer channel of the
reductant impingement device of FIGS. 2-4, according to an
embodiment of the present disclosure. The impingement device body
132 depicts a section view (Section B) of the outer channel 162,
according to an embodiment. The channel direction 166 indicates a
general trajectory of any fluids passing through the outer channel
162. The outer channel 162 may be configured as a slit having two
opposing inner channel walls. In one embodiment, the two outer
channel walls can include a first outer channel wall 174 that may
be disposed substantially parallel to a second outer channel wall
176. The two opposing channel walls form two sides of the outer
channel 162. In one aspect, the first outer channel wall 174 and
the second outer channel wall 176 are disposed at a second
predetermined angle 178 respective to the longitudinal axis of the
impingement pin 134 (e.g., the second longitudinal axis 150). In
one aspect, the second predetermined angle may be approximately
30.degree.. In another aspect, the first predetermined angle may be
another angle such as, for example, 25.degree., or 35.degree., or
greater or less than 25.degree., or 35.degree.. Notably, the
channel direction 164 (FIG. 5), which depicts the fluid trajectory
of fluids passing through the plurality of inner channels 152, may
be opposite to the channel direction 166, which depicts the fluid
trajectory of fluids passing through the plurality of outer
channels 156.
[0043] FIG. 7 is a schematic view of an exhaust system 180 for an
engine 188 that includes the nozzle 100, according to an embodiment
of the present disclosure. The exhaust system 180 may further
include an air compressor or other compressed air source 182
configured to supply compressed air 116 via a compressed air supply
line 190, and one or more reservoirs and pumps configured as a
reductant source 184. The reductant source 184 may be, for example,
a DEF tank configured to supply the reductant solution 114 via a
reductant solution supply line 186. The reductant solution supply
line 186 may be fluidly connected with the first inlet 108 (FIG.
1).
[0044] In some embodiments, an amount of compressed air 116 and/or
an amount of reductant solution 114 supplied to the system may be
associated with a flow rate of the exhaust stream 102, an
operational state of the engine 188 (e.g., rpm), a temperature of
the exhaust stream 102, a concentration of a particular gas in the
exhaust stream 102, and/or one or more other operating conditions
of the exhaust system 180. For example, as the flow rate of the
exhaust stream 102 decreases, a controller or other control
component (not shown) operably connected to an air compressor
and/or reductant pump may control the pump to commensurately
decrease the amount of reductant solution 114 and/or compressed air
116 supplied to the nozzle 100 (and thereby introduced into the
exhaust stream 102). Alternatively, as the flow rate of the exhaust
stream 102 increases, a controller or other control component (not
shown) may increase and/or decrease the amount of reductant
solution 114 and/or compressed air 116 supplied to the nozzle 100.
Consequently, the amount of reductant/air solution 120 introduced
into the exhaust stream 102 may be controllable by a
controller.
[0045] In some embodiments, the nozzle 100 may be located
downstream from a SCR system, or be operable as part of a SCR
system within an exhaust pipe 192 and/or other treatment systems.
The exhaust system 180 may also include one or more oxidation
catalysts, mixing features, particulate filters (e.g., diesel
particulate filter (DPF)), SCR substrates, ammonia reduction
catalysts, and other devices configured to further enhance the
effectiveness of reducing NOx (devices not shown). Additionally,
while only one nozzle 100 is shown, in some embodiments, the
exhaust system 180 may include more than one nozzle 100. Moreover,
the exhaust system 180 may include any number of exhaust pipes 192
having one or more nozzles 100 positioned therein.
INDUSTRIAL APPLICABILITY
[0046] The nozzle 100, impingement device 130, and exhaust system
180 may increase exhaust system efficiency and operability by
decreasing and/or eliminating crystallization of urea compounds or
other reactants due to adverse response to exhaust system heat. The
embodiments described herein may increase turbulence and mixing
within the nozzle 100 such that reductant solution 114 may be
maintained at operable temperatures while treating the exhaust
stream 102 in an exhaust system of a combustion engine.
[0047] While aspects of the present disclosure have been
particularly shown and described with reference to the embodiments
above, it will be understood by those skilled in the art that
various additional embodiments may be contemplated by the
modification of the disclosed machines, systems and methods without
departing from the spirit and scope of what is disclosed. Such
embodiments should be understood to fall within the scope of the
present disclosure as determined based upon the claims and any
equivalents thereof
* * * * *